Andrew Sielen put together an exhaustive analysis of the price of Lego sets over the years. Here are some highlights from his findings:

Contrary to popular perception the price of Lego has decreased over time.

We might think that Lego has become more expensive because while the average price per Lego piece has gone down, the number of Lego pieces in a set has gone up, meaning more expensive sets overall.

These new, more complex Lego sets are marketed to an older crowd who have deeper pockets and more of an interest in difficult projects.

Lego has also increased the number of sets it produces in a year. Retailers can only have so many Lego products on their shelves and they may be choosing to only stock the most expensive ones – thus contributing to the perception that the price of Lego has increased.

We might also think that Lego sets are now more expensive because when we were kids we never truly appreciated how much they cost.

Read much more over here. Sielen goes through the price per gram, the price of signature Lego sets, and presents a bunch of fascinating graphs.